The production of integrated circuits begins with the creation of high-quality semiconductor wafers. During the wafer fabrication process, the wafers may undergo multiple masking, etching, and dielectric and conductor deposition processes. Because of the high-precision required in the production of these integrated circuits, an extremely flat surface is generally needed on at least one side of the semiconductor wafer to ensure proper accuracy and performance of the microelectronic structures being created at the wafer surface. As the size of the integrated circuits continues to decrease and the number of microstructures per integrated circuits increases, the need for precise wafer surfaces becomes more important. Therefore, between some processing steps, it may be necessary to polish or planarize the surface of the wafer to obtain the flattest surface possible.
In an exemplary prior art polishing method, one side of the wafer is attached to a flat surface of a wafer carrier or chuck and the other side of the wafer is pressed against a flat polishing surface. To enhance polishing effectiveness, the wafer carrier may be rotated about its vertical axis and oscillated over the inner and outer radial surface of the polishing pad to enhance polishing. Such wafer carriers are known to those skilled in the art and may be employed in a number of processing machines, e.g., a chemical mechanical planarization (CMP) machine.
Wafer carriers may require occasional cleaning, replacement, or repair. Accordingly, technicians may need to remove the wafer carriers from the processing machines and manually handle the individual wafer carriers after they are freed. Many wafer carriers are bulky, heavy (e.g., up to 25 pounds), and difficult to lift, hold, and carry. For example, to lift a wafer carrier from a polishing platform, an operator may hold a portion of the carrier, slide the carrier to an edge of the polishing platform, manually support the carrier by placing his or her hand underneath the carrier, and lift the carrier. Due to the size and weight of the carrier, the operator may be tempted to hold the carrier against his or her body for additional support.
Manually handling a wafer carrier is undesirable for several reasons. For example, touching the lower surface of the carrier may damage the surface or deposit foreign matter onto the surface. If such foreign matter is not removed from the carrier prior to reinstallation, the delicate surfaces of the wafers may be damaged. In addition, touching the polishing surface and sliding the carrier over the polishing surface may damage the lower surface of the carrier and/or the polishing surface.
Manually handling heavy workpiece polishing carriers can be dangerous to the handler and other people or equipment in the working environment. For example, sliding and lifting a bulky carrier may expose the operator's hands and arms to injury. If a carrier is accidentally dropped, then the carrier itself will likely be damaged and surrounding equipment and personnel may be at risk.